Catatonia and its varieties: an update
Authors: Andrew Francis, Charles Mormando
Journal: World Psychiatry (2023)

Catatonia is being increasingly recognized in both clinical practice and ongoing research. Although originally described as a unique syndrome by Kahlbaum in 1874, it was associated with schizophrenia by Kraepelin and Bleuler in the early 1900s, and this nosological oversight was reflected in the first three editions of the DSM1. Fink and Taylor supported its separate categorization as a syndrome in 1991, prior to publication of the DSM-IV. They argued that catatonia occurs in many illnesses and is not simply a subtype of schizophrenia1. In the DSM-IV, “catatonia due to a general medical condition” was added, and “catatonic features” became a specifier for major depressive, manic and mixed episodes, although a “catatonic type” was still included for schizophrenia. Further classification progress was made in the DSM-5, influenced by a group of scholars who advocated the recognition of catatonia as a unique syndrome that warranted a single defined class2. Although the manual does not establish catatonia as a truly independent class, it lists “catatonia associated with another mental disorder” (i.e., a neurodevelopmental, psychotic, bipolar, depressive or other mental disorder), as well as “catatonic disorder due to another medical condition” and “unspecified catatonia”. Significant progress has also been made with the recent transition from the ICD-10 to the ICD-113. The ICD-10 coded catatonia as either “catatonia due to a known physiological condition” or “catatonic schizophrenia”. The ICD-11 explicitly conceptualizes catatonia as an independent syndrome, with the subtypes of “catatonia associated with another mental disorder” (emphasizing that the syndrome can occur “especially” in the context of autism spectrum disorder), “catatonia induced by substances or medications”, and “secondary catatonia syndrome” (when symptoms are judged to be the direct pathophysiological consequence of a medical condition). Specifiers for autonomic abnormalities in catatonia (including tachycardia or bradycardia, hypertension or hypotension, and hyperthermia or hypothermia) are also introduced. Diagnosing catatonia can be challenging, as operational definitions for catatonic signs, although available, are not well known by clinicians. Additionally, there is debate in the research literature about the number of signs necessary to diagnose the condition4. Two widely utilized symptom lists are the one included in the DSM-5 and the Bush-Francis Catatonia Rating Scale (BFCRS). The DSM-5 requires at least three out of a total of 12 signs (an incomplete list including stupor, catalepsy, waxy flexibility, mutism, negativism, posturing, mannerism, stereotypy, agitation, grimacing, echolalia and echopraxia). The manual does not define these signs well and lacks guidelines for severity. A study showed that, out of 232 cases of catatonia validated using a standardized rating scale and treatment response, only 73% met DSM-5 criteria5. The BFCRS contains 23 items, all operationally defined. It identifies a case by the presence of at least two of the first 14 items (immobility/stupor, mutism, staring, posturing/catalepsy, grimacing, echopraxia/echolalia, stereotypy, mannerism, stereotyped and meaningless repetition of words and phrases, rigidity, negativism, waxy flexibility, withdrawal, and excitement). The severity of catatonia is defined by rating all 23 items on a three-point scale. A standardized examination procedure is provided. The scale has been found to be highly reliable and sensitive to clinical change6. A problem with the DSM-5 is that the diagnosis of catatonia is disallowed in the presence of delirium. The empirical basis for this exclusion is not provided, and systematic reports of catatonia co-existing with delirium continue to emerge in the literature. Perhaps the best example is a study that prospectively assessed 136 critically ill patients7, finding that 31% of them fulfilled criteria for both catatonia and delirium using DSM-5 criteria, while 43% had delirium alone. No treatment interventions were reported. This study also helped to address the dilemma of the number of signs necessary to diagnose catatonia: sensitivity and specificity were 91% after increasing the screening threshold to four signs rather than two on the BFCRS. This is an important diagnostic consideration, as there is potential for reduced specificity in such medically complex populations. Delirious mania is a syndrome (unrecognized by the DSM and ICD systems) that adds to the nosological dilemma of co-existing delirium and catatonia. This is a syndrome of catatonic excitement, delirium and psychosis, first described in 1849 by Bell and repopularized by Fink in 19994. There are no formal diagnostic criteria for this syndrome, as the literature on diagnosis and treatment is sparse. It may be worsened by antipsychotic medications and, despite the presence of delirium, benzodiazepines are effective and treatment with electroconvulsive therapy (ECT) typically results in resolution of the syndrome4. Consensus is lacking as to whether delirious mania is best classified as a feature of bipolar spectrum illness, a severe form of catatonia, or another clinical syndrome altogether. There is further nosological confusion at the interface of neuroleptic malignant syndrome (NMS) and catatonia. Neither DSM nor ICD systems recognize NMS as a subtype or variant of catatonia; however, many catatonia scholars view NMS as another prototype of malignant catatonia, differing only in its precipitation by dopamine antagonists. NMS cases score on catatonia rating scales and respond to benzodiazepines and ECT4. Rather than being a distinct entity, it seems more likely that NMS lies on the same spectrum of illness as catatonia. As alluded to in the ICD-11, catatonia is being increasingly recognized in people with autism spectrum disorder, with a recent meta-analysis reporting that the syndrome is present in 10.4% of these patients8. Catatonia is often undiagnosed in this population, as certain catatonic signs – such as repetitive speech and behaviors, purposeless agitation, self-injury, and stereotyped motor movements – are usually explained as inherent manifestations of autism itself. Indeed, the differential diagnosis may be difficult. Although there are no prospective studies, case reports and clinical reviews indicate that catatonia in these patients can be effectively treated with ECT4. Anti-N-methyl-d-aspartate (NMDA) receptor encephalitis is another syndrome where catatonia is being increasingly recognized, which again presents nosological implications, as many of these patients are also delirious. In a recent prospective study of over 600 patients with the above diagnosis, catatonia was identified in 59% of the cases, and catatonia with delirium in 58% of them9. Proper identification of catatonia associated with this complex neuropsychiatric syndrome is important, as 12% of patients from this study developed NMS after administration of antipsychotic medication. ECT seems to be safe and effective in these patients, occasionally even without immune modulating treatment9. Despite these many varieties, catatonia remains a recognizable and treatable syndrome across the many psychiatric and medical conditions where it is seen. The nosological implications of the emerging research evidence are clear. This evidence suggests that catatonia lies on a spectrum of illness interfacing with mood disorder, psychotic disorder, delirium, neurological illness and other medical conditions. All psychiatrists should become familiar with the detection and treatment of this syndrome, as well as with its multiple varieties.